If a physician reads radiology xrays, EKGs, etc and the biller missed billing the professional component (due to paper shuffle, some may be missed), is that "illegal"?

A biller at our office says that it will harm the patient and it will cause trouble for the practice?

She also says that if insurances didn’t get the code the xray to specificity the patient might get future services denied by insurances? (E.g. arthritic degeneration of knee if not coded, may get denied for knee replacement surgery)

I’m not understanding why insurances would base on codes and not the physician’s notes. Most of these procedures require pre auth.

Thanks for clarifying.